And suddenly a so-called Windows2000 announces me that I have committed an illeagal operation. Could somebody kindly tell me if there is a way (there must be a way...) to overcome this unexpected obstacle?

Sure. The best way to overcome this obstacle is to not downgrade to the latest Microsoft Operating Systems.

In fact, I was using Win95 until last year when I downgraded to Win98. I don't plan on downgrading to Win2000 nor to XP. I expect my next upgrade will actually be to Linux which I'm currently running in parallel.

Good luck,
Craig Steiner